Method for producing an orthodontic appliance having a vibrating element

ABSTRACT

The present invention concerns an orthodontic appliance for accelerating the tooth aligning effect and shortening the treatment period, and has an object to provide an appliance which can bring about higher aligning effect than usual ways by giving vibration to tooth to be aligned to activate bone remodeling of the targeted tooth and the alveolar bone and enhance the shift of the tooth. This appliance includes a vibrating element and a dental mouthpiece having the vibrating element built therein. The provision of the vibrating element in the dental mouthpiece facilitates the application of vibration and handling, and continues the treatment safely even at home. The inner shape of the dental mouthpiece serves aligning treatment as well as acceleration of the effect.

The present application is a division of U.S. application Ser. No.11/721,085, filed Jun. 7, 2007, which is a National Stage Application ofPCT/JP2007/56040, filed Mar. 23, 2007, the disclosures of whichincorporated herein by reference in their entireties.

TECHNICAL FIELD

The present invention relates to an orthodontic appliance.

BACKGROUND ART

An orthodontic appliance equipped with an orthodontic wire to be mountedon teeth has been conventionally known. An elastic restoring force ofthe orthodontic wire acts as a constant static load on the teeth tocorrect teeth malalignment or crossbite. In other words, the orthodonticappliance is based on the principle of aligning the teeth by graduallydeforming an alveolar bone supporting the teeth through the applicationof a constant force to the teeth, or bone remodeling.

However, the teeth alignment using the orthodontic wire takes a verylong time (fastest six months, normally several years) until anorthodontic treatment is finished. This is likely to become a cause togive up the treatment easily.

In order to shorten a period of such an orthodontic treatment,technology of giving a vibration force to the teeth has been studied.For example, a study result to the effect that if a sample A in which aconstant force was applied to the teeth and a sample B in which avibration force was applied to the teeth are compared, the sample B towhich the vibration force was applied is more effective in shorteningthe period as shown in FIG. 17A is disclosed in non-Patent Literature 1.

Similarly, a study result to the effect that if a sample C in which aconstant force was applied to the teeth and a sample D in which aconstant force and a vibration force were applied to the teeth arecompared, the sample D to which the constant force and vibration forcewere applied is more effective in shortening the period as shown in FIG.17B is disclosed in non-Patent Literature 2.

According to these studies, the application of the vibration force tothe teeth remarkably shortens the period of orthodontic treatment toabout ½ to ⅓ as compared to conventional technologies. Further, it issufficient to apply a vibration force only for 1.5 hours a day accordingto the former Literature and only for 2 minutes at a time and once everytwo weeks according to the latter Literature.

It can be understood from these studies that the teeth alignment byapplying a vibration force as well as a constant force to the teeth ismore effective in remarkably shortening the period of orthodontictreatment than the teeth alignment only by applying a constant force tothe teeth using an orthodontic wire or the like.

Appliances for putting the above studies to practical use have beenconventionally proposed. Specifically, Patent Literature 1 discloses anappliance provided with a dental mouthpiece to be mounted on the teethto urge movements of teeth to be aligned and means for applyingultrasonic vibration to tissues surrounding the mounted position of thedental mouthpiece. Further, Patent Literature 2 discloses an appliancefor applying ultrasonic vibration to teeth to be aligned.

However, the appliances disclosed in the above Patent Literatures 1, 2have a problem that ultrasonic vibration cannot be efficiently appliedto the teeth to be aligned since both of them receive the application ofultrasonic vibration from the outside, for example, by pressing anultrasonic head against the cheek skin. Further, since the respectiveappliances require an ultrasonic generator, there is also a problem thattreatment cannot be continued unless a patient goes to a dental clinicequipped with these appliances.

-   [Non-Patent Literature 1] Shimizu: “Journal of Japan Orthodontic    Society” 45, pp. 56-72, 1986-   [Non-Patent Literature 2] Ohmae et al.: “Journal of Japan    Orthodontic Society” 60(4), p. 201, 2001-   [Patent Literature 1] Japanese Unexamined Patent Publication No.    2002-102255-   [Patent Literature 2] Japanese Unexamined Patent Publication No.    2004-201895

DISCLOSURE OF THE INVENTION

The present invention has been worked out to solve the above problems,and has an object to provide an orthodontic appliance which canprecisely apply vibration to tooth to be aligned and enables a treatmentto be easily and safely continued even at home.

In order to accomplish the object, the present invention is directed toan orthodontic appliance for aligning teeth including a tooth to bealigned, comprising a vibrating element for generating mechanicalvibration and applying the vibration to the tooth to be aligned; and adental mouthpiece having the vibrating element built therein andmountable on the teeth with the vibrating element built therein.

Since the vibrating element for generating the mechanical vibration(mechanical stimuli) is built in the dental mouthpiece to be mounted onthe teeth in this appliance, the vibrating element can efficiently applythe vibration to the tooth to be aligned. Further, the storage of thevibrating element in the dental mouthpiece enables a treatment to beeasily and safely continued at any desired time, for example, at homewithout going to a dental clinic to apply mechanical vibration.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a dental cast of a lower dental arch.

FIG. 2 is a perspective view showing a state where a dental mouthpieceaccording to a first embodiment of the invention is mounted on teeth.

FIG. 3 is an exploded perspective view showing the dental mouthpiece ofFIG. 2 when viewed from topside.

FIG. 4 is an exploded perspective view showing the dental mouthpiece ofFIG. 2 from underside.

FIG. 5A is a section along the line VA-VA in FIG. 2, FIG. 5B is asection along the line VB-VB in FIG. 2 and FIG. 5C is a connectiondiagram of an electric motor.

FIG. 6 is a perspective view showing a state where a dental mouthpieceaccording to a second embodiment of the invention is mounted on teeth.

FIGS. 7A and 7B show a dental mouthpiece according to a third embodimentof the invention, wherein FIG. 7A is an exploded perspective view andFIG. 7B is a section along the line VIIB-VIIB in FIG. 7A.

FIGS. 8A and 8B are sections corresponding to the one along the lineVIIB-VIIB in FIG. 7A and showing other constructions.

FIGS. 9A and 9B show a dental mouthpiece according to a fourthembodiment of the invention, wherein FIG. 9A is a perspective view andFIG. 9B is a section along the line IXB-IXB in FIG. 9A.

FIG. 10 is a perspective view showing a dental mouthpiece according to afifth embodiment of the invention.

FIG. 11A is a perspective view of a dental mouthpiece according to asixth embodiment of the invention, FIG. 11B is a plan view showing auser and a magnetic field generating coil, and FIG. 11C is a front viewshowing the user and the magnetic field generating coil.

FIG. 12 is a diagram showing the process of producing a dentalmouthpiece according to the present invention.

FIG. 13A is a perspective view of a dental mouthpiece according to aseventh embodiment of the invention, and FIG. 13B is an enlarged sectionshowing an essential portion.

FIG. 14A is a perspective view of an electric motor portion of a dentalmouthpiece according an eighth embodiment of the invention, and FIG. 14Bis an enlarged section showing an essential portion.

FIG. 15A is a section showing a state at the time of inserting a tube ina tube connecting structure utilizing the dental mouthpiece according tothe seventh embodiment of the invention, FIG. 15B is a section showing astate at the time of welding the tube, and FIG. 15C is a section afterthe tube is welded.

FIG. 16A is a section before connecting a connector in a tube connectingstructure utilizing the dental mouthpiece of the eighth embodiment ofthe invention, and FIG. 16B is a section after the connector is coupled.

FIGS. 17A and 17B are graphs respectively showing an effect ofshortening a period of orthodontic treatment.

FIG. 18 is a perspective view showing one example of a dental mouthpieceproducing apparatus according to the invention.

FIG. 19 is a diagram showing a first example of a dental mouthpieceproducing method of the invention using the producing apparatus shown inFIG. 18.

FIG. 20 is a diagram showing a second example of the dental mouthpieceproducing method of the invention using the producing apparatus shown inFIG. 18.

FIGS. 21A and 21B are diagrams showing the process of casting a dentalmouthpiece using an EVA sheet.

FIG. 22 is a perspective view showing a state where a dental mouthpieceaccording to a ninth embodiment of the invention is mounted on teeth.

FIG. 23 is a perspective view showing a state where a dental mouthpieceaccording to a tenth embodiment of the invention is mounted on teeth.

FIG. 24 is a perspective view showing a dental mouthpiece according toan eleventh embodiment of the invention.

FIG. 25 is a perspective view showing a dental mouthpiece according to atwelfth embodiment of the invention.

FIG. 26 is a perspective view showing a dental mouthpiece according to athirteenth embodiment of the invention.

FIG. 27 is a perspective view showing a state where a dental mouthpieceaccording to a fourteenth embodiment of the invention is mounted onteeth.

FIG. 28 is a perspective view showing a dental mouthpiece according to afifteenth embodiment of the invention.

FIG. 29 is a perspective view showing a state where a dental mouthpieceaccording to a sixteenth embodiment of the invention is mounted on teethof the lower dental arch of a user.

FIG. 30 is a section along the line 30-30 in FIG. 29.

FIG. 31 is an exploded perspective view showing the dental mouthpieceaccording to the sixteenth embodiment of the invention when viewed fromtopside.

FIG. 32 is a graph showing an experiment result of the inventors of thepresent application.

FIG. 33 is a perspective view of an example of a dental mouthpiecesimilar to the dental mouthpiece according to the sixteenth embodimentof the invention, but adopting a different orthodontic method.

FIG. 34 is a perspective view showing a state where a dental mouthpieceaccording to a seventeenth embodiment of the invention is mounted on adental cast of a user.

FIG. 35 is a perspective view showing a state where a dental mouthpieceaccording to an eighteenth embodiment of the invention is mounted onteeth.

FIG. 36 is a perspective view showing a state where a dental mouthpieceaccording to a nineteenth embodiment of the invention is mounted onteeth.

FIG. 37 is a diagram showing a method for producing a dental mouthpiecehaving an inner surface form in conformity with a user's dental casthaving braces mounted thereon.

FIG. 38 is a perspective view showing a state where a mouthpieceaccording to a twentieth embodiment of the invention is mounted on auser's lower dental arch.

FIG. 39 is a perspective view of a dental cast of the user's lowerdental arch.

FIG. 40 is a section along the line 40-40 in FIG. 38.

FIG. 41 is an exploded perspective view showing the constructions of avibration actuator and a flexible board.

FIG. 42 is a section of the dental mouthpiece according to the twentiethembodiment of the invention, an electric motor built in the dentalmouthpiece and a flexible board.

FIG. 43 is a diagram showing a method for producing the dentalmouthpiece according to the twentieth embodiment of the invention.

FIG. 44 is a plan view of a flexible board in a dental mouthpieceaccording to a twenty first embodiment of the invention.

BEST MODES FOR EMBODYING THE INVENTION

Hereinafter, best modes for embodying the present invention aredescribed in detail with reference to the accompanying drawings.

A first embodiment of the present invention is described with referenceto FIGS. 1 to 5. FIG. 1 is a perspective view of a dental cast 1 of alower dental arch according to this embodiment, and FIG. 2 is aperspective view showing a state where a dental mouthpiece 7 accordingto this embodiment is mounted on teeth 3 of the dental cast 1.

The teeth 3 shown in FIG. 1 are comprised of teeth 3 a to 3 n, whereinthe teeth 3 a, 3 n are posterior teeth. Braces are mounted on the teeth3 b to 3 m excluding these posterior teeth. These braces include aplurality of brackets 4 to be fixed to the buccal surfaces of the teeth3 b to 3 m and an orthodontic wire (arch wire) 5 arranged to connectthese brackets 4. This orthodontic wire 5 is latched to the teeth 3 b to3 m by the respective brackets 4. The orthodontic wire 5 is elasticallydeformably latched, so that an elastic restoring force thereof acts as aconstant static load on the teeth 3. The application of this static loadcorrects malocclusion. It should be noted that braces for aligning thedentition are not limited to the one shown in FIG. 1.

An orthodontic appliance according to this embodiment is provided withan electric motor 8 and a dental mouthpiece 7 as shown in FIGS. 2 and 3.

The dental mouthpiece 7 is mounted on teeth to be aligned, e.g. theteeth 3 having the orthodontic wire 5 mounted thereon. FIG. 3 is anexploded perspective view of the dental mouthpiece when viewed fromtopside, and FIG. 4 is an exploded perspective view of the dentalmouthpiece 7 when viewed from underside.

The dental mouthpiece 7 has an inner and outer overlaid structure.Specifically, the dental mouthpiece 7 is comprised of an inner layer 7Ato be directly mounted on the teeth 3 and an outer layer 7B mounted onthe outer side of the inner layer 7A as shown in FIG. 5A.

The inner and outer layers 7A, 7B are preferably cast into suitableshapes using a material normally used for ordinary mouthpieces andhaving guaranteed hygienic safety, e.g. an EVA (ethylene vinyl acetate)sheet which is a polymer material (method for producing the dentalmouthpiece 7 is described later). Such a material is preferable sincehaving little influence such as side effects on teeth and gingivaltissues.

The material of the dental mouthpiece according to the present inventionis not limited to the EVA sheet. However, the EVA sheet is preferablebecause it has a high electrically insulating property and functions asa heat insulating material. Particularly, the application of the EVAsheet to the inner layer 7A can make the inner layer 7A softer. The softinner layer 7A can alleviate the transmission of mechanical vibration(particularly high-speed components) from the electric motor 8 to bedescribed later to the teeth 3 g, 3 h to be aligned. The alleviation oftransmission of such vibration effectively suppresses damages of theteeth 3 g, 3 h to be aligned.

The electric motor 8 constitutes a vibrating element for generatingmechanical vibration and is built in the dental mouthpiece 7. Since theelectric motor 8 is built in, a bulge portion 7 a as shown in FIG. 5B isformed at a part of the outer layer 7B corresponding to the teeth 3 g, 3h to be aligned. A clearance for storing the electric motor 8 is definedbetween the inner surface of the bulge portion 7 a and the outer surfaceof the inner layer 7A.

The electric motor 8 is small-sized and lightweight and generatesvibration to accelerate the orthodontic alignment effect. The electricmotor 8 is horizontally stored in the above clearance (i.e. in such aposture that the direction of the vibration is substantially normal tothe teeth 3). This electric motor 8 has an eccentric rotary portionwhich is rotatable about a specified axis and whose center of gravity isdeviated from this axis, wherein the rotation of the eccentric rotaryportion induces mechanical vibration. The above rotary portion may, forexample, be comprised of a rotary shaft and an eccentric weight mountedat a position deviated from the central axis of this rotary shaft. Anelectric motor generally used as a vibrator for a mobile phone or thelike can be used as the electric motor 8.

The inner layer 7A is mounted inside the outer layer 7B with theelectric motor 8 stored in the bulge portion 7 a. Further, the outersurface of the inner layer 7A and the inner surface of the outer layer7B are joined airtight, for example, by thermal welding or ultrasonicwelding so that saliva, cleaning liquid or the like does not enter thebulge portion 7 a through the interfaces, and these pieces 7A, 7B areunited by this joining. The airtightness is sufficient if the inside ofthe bulge portion 7 a is held watertight to such an extent that moisturedoes not actually enter.

In this embodiment, the electric motor 8 is a direct-current (DC) motor.This orthodontic appliance includes a battery 11 as shown in FIGS. 2 and5C as a direct-current source for the electric motor 8, and the electricmotor 8 is connected with this battery 11 via a feeder cable 9. Thefeeder cable 9 is drawn out of the dental mouthpiece 7 from the electricmotor 8 through a though hole 7 f formed in the bulge portion 7 a whileholding the inside of the bulge portion 7 a of the outer layer 7Bairtight, and further drawn out of the mouth between the lips to beconnected with the battery 11 via a variable resistor 10 and a switch12.

The variable resistor 10 and the battery 11 are, for example, placed ona desk or the like near a user (patient) wearing the dental mouthpiece7. The variable resistor 10 changes a DC current level to be supplied tothe electric motor 8. The adjustment of the DC current level by thisvariable resistor 10 enables the adjustment of the rotating speed of theelectric motor 8, i.e. the adjustment of frequency. A vibrationfrequency (frequency) to be adjusted is not specifically limited, but ispreferably about several Hz to several hundreds Hz, for example. Analternating-current (AC) motor may be used as the electric motor 8.

Next, one example of the method for producing the dental mouthpiece 7 isdescribed with reference to FIG. 12.

In Step S1 shown in FIG. 12, a dental impression is obtained byattaching an impression material to teeth 3 of a user. After obtainingthe dental impression, the tray with impression material is taken outfrom the teeth 3 while keeping the teeth shape, and plaster is pouredinto this impression material. This plaster is taken out from theimpression material after being hardened. In this way, a plaster modelof dentition E for the user is completed (Step S2).

If the braces including the brackets 4 and the orthodontic wire 5 aremounted on the teeth 3 of the user, the inner layer 7A might be brokenor the brackets 4 might be disengaged from the teeth by the inner layer7A getting caught by edges of the braces upon mounting the inner layer7A of the dental mouthpiece 7 on the teeth 3. In order to prevent suchproblems, wax or the like can be filled into clearances in parts of thedental cast E corresponding to the brackets 4 and the orthodontic wire 5to eliminate the edges. This method reduces burdens on the user ascompared to a method according to which dental impression is carried outafter nontoxic wax or the like that can be washed away with water isfilled into clearances of the brackets 4 and the orthodontic wire 5before the impression material is attached to the teeth 3.

An EVA sheet softened by heating is placed on the teeth plaster model Eof Step S2, and suction casting is applied. After this EVA sheet iscooled, the inner layer 7A is completed by taking the teeth plastermodel E from the EVA sheet (Step S3).

Inner layers having different thicknesses can be fabricated by changingthe thickness of the EVA sheet. The use of the thin inner layer 7Aimproves wearing comfort and improves the transmission characteristic ofmechanical vibration from the electric motor 8. It is also possible tochange the transmission characteristic of mechanical vibration to theindividual teeth 3 a to 3 n by changing the thickness of the inner layer7A for each tooth 3 a to 3 n.

The inner layer 7A is fitted to the teeth plaster model E (Step S3), anda dental impression is performed anew using silicon resin or the like inthis state (Step S4). Plaster is poured into the completed silicon cast,and is taken out after being hardened. In this way, an inner layerplaster model F is completed (Step S5).

A plaster model F′ that becomes the bulge portion 7 a of the outer layer7B is adhered to the inner layer plaster model F (Step S6). Further, anEVA sheet softened by heating is placed on the inner layer plaster modelF, and suction casting is applied. After this EVA sheet is cooled, theouter layer 7B is completed by taking the inner layer plaster model Ffrom the EVA sheet (Step S7).

Thereafter, the inner layer 7A is fitted inside the outer layer 7B withthe electric motor 8 stored in the bulge portion 7 a of the outer layer7B. In this state, the outer surface of the inner layer 7A and the innersurface of the outer layer 7B are joined airtight by means of ultrasonicwelding or adhesive to be united, whereby the dental mouthpiece 7 iscompleted (Step S8). The total thickness of the dental mouthpiece 7 ispreferably about 1 to 6 mm.

The outer surface of the inner layer 7A and the inner surface of theouter layer 7B may be joined only at the peripheral edge portion of thebulge portion 7 a of the outer layer 7B storing the electric motor 8.However, in light of cleaning and storage of the inner layer 7A and theouter layer 7B, and also cleaning and storage of the dental mouthpiece 7after the use of it, it is preferable to join the entire outerperipheral edges of the inner layer 7A and the outer layer 7B airtight.

Since the electric motor 8 for generating mechanical vibration(mechanical stimuli) is built in the dental mouthpiece 7 to be mountedon the teeth 3 in the orthodontic appliance according to thisembodiment, vibration can be efficiently applied to the teeth 3 g, 3 hto be aligned. Particularly, since the electric motor 8 according tothis embodiment is stored in the part of the dental mouthpiece 7corresponding to the teeth 3 g, 3 h to be aligned, vibration can beprecisely applied to the teeth 3 g, 3 h to be aligned.

Further, the storage of the electric motor 8 in the dental mouthpiece 7enables the treatment to be easily and safely continued at any desiredtime, for example, at home even without going to a dental clinic.

Furthermore, since the mechanical vibration of the electric motor 8 istransmitted to the teeth 3 g, 3 h to be aligned via the inner layer 7A,pains to the teeth resulting from the direct transmission of mechanicalvibration to the teeth 3 g, 3 h to be aligned can be mitigated.

Further, the sealed storage of the electric motor 8 in the dentalmouthpiece 7 is hygienic and enables water-washing.

The electric motor 8 as the vibrating element is inexpensive.Particularly, the electric motor for generating mechanical vibration bythe rotation of the eccentric rotary portion is more inexpensive since asmall-sized and lightweight electric motor generally used as the oneprovided with a vibrator function can be used as it is.

In the case where the electric motor 8 generates mechanical vibration bythe rotation of the eccentric rotary portion, the direction of therotary shaft of the electric motor 8 and the direction of the teethcoincide with each other if the electric motor 8 is stored in the dentalmouthpiece 7 such that the vibrating direction is substantially normalto the teeth 3. The coincidence of these directions reducesuncomfortable feeling by reducing the projecting height from the dentalmouthpiece 7 even if the electric motor 8 is long along the rotary shaftthereof. Further, since the vibrating direction of the electric motor 8is normal to the teeth, the vibration of the electric motor 8 can beimparted to the teeth efficiently.

If the electric motor 8 is driven by a direct-current (DC) power source,the frequency (rotating speed) of the electric motor 8 can be easilyadjusted through the adjustment of a direct-current voltage level by thevariable resistor 10. Further, the use of the battery 11 as thedirect-current power source enables a treatment in such a place wherethere is no AC outlet (e.g. outdoors).

Since the dental mouthpiece 7 is so shaped as to be mountable on theentire teeth 3, the electric motor 8 as the vibrating element forgenerating mechanical vibration can be precisely positioned at the teeth3 g, 3 h by mounting the dental mouthpiece 7 on the teeth 3.

If the electric motor 8 is held in direct contact with the inner surfaceof the bulge portion 7 a or the like, a vibration force outputted by theelectric motor 8 is likely to be restrained. Therefore, the electricmotor 8 is preferably accommodated in a cover made of metal or resin(e.g. ABS resin) so that the vibration force is not restrained, andstored into the clearance in the bulge portion 7 a together with thecover in this state.

For example, as shown as a seventh embodiment in FIGS. 13A and 13B, acover 20 made of metal or resin and having a cylindrical shape with aclosed top may be fitted on the casing of the electric motor 8 toenclose the eccentric weight 8 a of the electric motor 8, and theelectric motor 8 may be stored into the clearance in the bulge portion 7a together with the cover 20 in this state.

Alternatively, the electric motor 8 may be mounted on a rectangularflexible printed board 21 as shown as an eighth embodiment in FIGS. 14A,14B. A pair of power supply conductors 21 a, 21 b extending inlengthwise direction are formed on the flexible printed board 21. Powerfeed terminals (not shown) that can respectively come into contact withthe conductors 21 a, 21 b are formed on the underside of the electricmotor 8, and the mount position of the electric motor 8 on the flexibleprinted board 21 is adjustable in a direction along the conductors 21 a,21 b. The electric motor 8 is fixed to the flexible printed board 21 bysoldering the power feed terminals of the electric motor 8 and theconductors 21 a, 21 b to each other after the mount position isadjusted. Further, power feed terminals (not shown) of one connector(e.g. male connector) 22 can be soldered to the conductors 21 a, 21 b ofthe flexible printed board 21.

A cover 24 made of metal or resin and having a semicylindrical shapewith a closed top is mounted around the casing of the electric motor 8.This cover 24 includes a plurality of claws 24 a, and the flexibleprinted board 21 is formed with a plurality of locking holes 21 c alongthe conductors 21 a, 21 b. The claws 24 a are engaged with suitable onesof the locking holes 21 c at positions where the cover 20 encloses theeccentric weight 8 a of the electric motor 8, and the electric motor 8is stored together with the cover 24 into the clearance inside the bulgeportion 7 a in this engaged state.

The dental mouthpiece 7 is formed with a covering portion 7 e continuouswith the bulge portion 7 a and adapted to cover the one connector 22airtight, and another connector (e.g. female connector) 23 is detachablyconnected with the connector 22 in the covering portion 7 e in anorthogonal direction. When being connected with the one connector 22,the other connector 23 is also covered airtight by the covering portion7 e. To the other connector 23 is coupled a power feed cable 9, which isdrawn out of the connector 23 to the outside while keeping the airtightstate and is pulled out of the mouth between the lips.

The power feed cable 9 of the electric motor 8 shown in FIGS. 13A and13B is also drawn out to the outside through the through hole 7 f formedin the bulge portion 7 a of the outer layer 7B while keeping theairtight state. This part of the dental mouthpiece 7 where the cable 9is drawn out is preferably completely waterproofed since the dentalmouthpiece 7 is fully water-washable. An exemplary structure for thispurpose is shown in FIG. 15.

A tube 25 as shown in FIG. 15A is used in this structure. This tube 25has an insertion hole 25 a formed in its central part through which thepower feed cable 9 is inserted, and a flange 25 b is formed at theleading end of the tube 25. This tube 25 is optimally made of the samematerial as the dental mouthpiece 7, i.e. EVA (ethylene vinyl acetate).The use of EVA enables excellent unification. The tube 25 preferably hassuch a length as to be sufficiently drawn out of the mouth between thelips.

The power feed cable 9 is inserted into the insertion hole 25 a from theside of the flange 25 b, and the flange 25 b is pressed into closecontact with the side surface of the bulge portion 7 a as shown in FIG.15B. The outer surface of the bulge portion 7 a and that of the tube 25are covered by heat insulating materials 26A, 26B in this close contactstate. With only a part near the flange 25 b exposed, the flange 25 b iswelded to adhere airtight to the side surface of the bulge portion 7 aas shown in FIG. 15C. The welding can be accomplished by theabove-mentioned thermal welding, ultrasonic welding or the like.

The structure obtained in this way can better improve the watertightnessof the part of the dental mouthpiece 7 where the power feed cable 9 isdrawn out to enable the accomplishment of complete watertightness ascompared to the case where the power feed cable 9 is merely drawn out tothe outside through the through hole if of the bulge portion 7 a of theouter layer 7B. Further, since the covering of the power feed cable 9 bythe tube 25 made of EVA hinders the contact of the power feed cable 9with the buccal cavity, hygienic safety can be guaranteed even if thepower feed cable 9 is, for example, made of vinyl chloride. Theappearance can also be improved.

The power feed cable 9 of the other connector 23 shown in FIGS. 14A and14B is also drawn out to the outside from the connector 23 in anairtight manner. This drawn-out part is also preferably completelywaterproofed since the dental mouthpiece 7 is fully water-washable. Anexemplary structure for this purpose is shown in FIG. 16.

A tube 25 as shown in FIG. 16A is used in this structure. This tube 25also has an insertion hole 25 a formed in its central part through whichthe power feed cable 9 is inserted, and a tubular portion 25 c is formedat the leading end of the tube 25. This tubular portion 25 c covers theother connector 23 and projects further forward. This tube 25 isoptimally made of the same material as the dental mouthpiece 7, i.e. EVA(ethylene vinyl acetate). The tube 25 preferably has such a length as tobe sufficiently drawn out of the mouth between the lips.

The covering portion 7 e continuous with the bulge portion 7 a has sucha tubular shape fittable inside the tubular portion 25 c of the tube 25in an airtight manner. The other connector 23 is detachably connectablewith the connector 22 in the covering portion 7 e from the outside in anorthogonal direction with the covering portion 7 e fitted inside thetubular portion 25 c.

This structure can better improve the watertightness of the part of thedental mouthpiece 7 where the power feed cable 9 is drawn out to enablethe accomplishment of complete watertightness as compared to the casewhere the power feed cable 9 is merely drawn out to the outside from theother connector 23. Further, since the covering of the power feed cable9 by the tube 25 made of EVA hinders the contact of the power feed cable9 with the buccal cavity, hygienic safety can be guaranteed even if thepower feed cable 9 is, for example, made of vinyl chloride. Theappearance can also be improved.

It should be noted that an embodiment using a flexible board isdescribed in detail as a twentieth embodiment later.

As shown as a second embodiment in FIG. 6, the dental mouthpiece 7 maybe so shaped as to be mountable on a part (teeth 3 f to 3 h to bealigned in the example of FIG. 6) of the teeth 3. The dental mouthpiece7 having such a shape is small in size and reduces burdens on the userat the time of wearing the dental mouthpiece 7.

The dental mouthpiece 7 is normally also mounted on an alveolar portionof the dental cast 1. However, part of the dental mouthpiece 7corresponding to the alveolar portion may be cut off in order to applymechanical vibration only to the teeth 3. Such cutting reduces the massof the dental mouthpiece 7, facilitates the vibration transmission andmakes the dental mouthpiece 7 smaller.

Since the dental mouthpiece 7 of this embodiment is mounted on theentire teeth 3, it is comprised of the inner layer 7A to be directlymounted on the teeth 3 and the outer layer 7B to be mounted on the innerlayer 7A. However, the inner layer 7A may be in the form of arectangular piece as shown as a third embodiment in FIGS. 7A and 7B.This inner layer 7A in the form of a rectangular piece is united withthe outer layer 7B by being joined airtight with the inner side of theouter layer 7B having the electric motor 8 stored in the bulge portion 7a in such a manner as to cover an opening of the bulge portion 7 a. Inthis appliance, the outer layer 7B is directly mounted on the teeth 3and the inner layer 7A functions as a mere sealing member to be joinedwith the outer layer 78 airtight.

Conversely, a recess for storing the vibrating element may be formed ata part of the inner layer 7A to be mounted on the teeth 3 and the outerlayer 7B may be locally joined with the inner layer 7A in such a manneras to cover the vibrating element fitted into the recess from the outerside.

It is also possible to store a drive power source, a controller and thelike for the electric motor 8 together with the electric motor 8 as thevibrating element in the dental mouthpiece 7 having the inner and outeroverlaid structure. Such storage eliminates the need to draw the powerfeed cable from the dental mouthpiece 7 out of the mouth between thelips and connect it with an external device (battery, controller or thelike).

For example, in an appliance shown as a fourth embodiment in FIGS. 9Aand 9B, a small-sized button battery 11′ is used as a power source forthe electric motor 8. An outer layer 7B is additionally formed with abulge portion 7 d for storing the button battery 11′ in the vicinity ofthe bulge portion 7 a for storing the electric motor 8. The electricmotor 8 and the button battery 11′ can be directly connected with eachother by a power feed cable or the like in both bulge portions 7 a, 7 d.A switch 13 that is alternately turned on and off every time beingpushed from the outer surface of the outer layer 7B can be incorporatedinto the power feed cable or the like.

The electric motor (vibrating element) 8, the button battery 11′, theswitch 13 and the like stored in the dental mouthpiece 7 are preferablyinsulated from each other. An ordinary insulation process may be appliedfor this insulation or the insulating property of the material of thedental mouthpiece 7 itself may be utilized, i.e. the dental mouthpiece 7may be partially used as insulation walls.

It is also possible to store a flexible board forming a control unit inthe dental mouthpiece 7. By mounting circuit elements such as avibrating element, a drive power source and a controller therefor onthis flexible board, the circuit elements can be more easily built inthe dental mouthpiece 7. This mounting enables wiring and coupling withthe outside to be omitted, enables the appearance of the appliance to bedefined only by the dental mouthpiece, and enables high electricalsafety to be ensured by hindering the contact of the power feed cable 9with the inside of the buccal cavity. An improvement in wearing comfortcan also be expected. Further, the practical value of the appliance canbe increased by making the appliance portable.

In the foregoing embodiments, the bulge portion 7 a is formed only atone position (position corresponding to the teeth 3 g, 3 h to bealigned) of the outer layer 7B of the dental mouthpiece 7. However, thebulge portions 7 a may be formed at a plurality of positions (e.g.positions corresponding to the teeth 3 g, 3 h to be aligned and theteeth 3 c, 3 d to be aligned as shown as a fifth embodiment in FIG. 10)of the outer layer 7B of the dental mouthpiece 7 and the electric motor8 may be stored in each of these bulge portions 7 a.

In the foregoing embodiments, the outward projecting bulge portion 7 ais formed at the part of the front side of the outer layer 7Bcorresponding to the teeth 3 g, 3 h to be aligned and the electric motor8 is horizontally stored in this bulge portion 7 a. However, an inwardprojecting bulge portion 7 a′ may be formed at a part of the rear sideof the outer layer 7B corresponding to a tooth 3 l to be aligned and theelectric motor 8 may be vertically stored in this bulge portion 7 a′ asshown in FIG. 10.

Although the dental mouthpiece 7 according to the foregoing embodimentshas the overlaid structure comprised of the inner layer 7A and the outerlayer 7B, the dental mouthpiece according to the present invention mayhave a multilayer structure comprised of three, four or more layers.

The vibrating element according to the present invention is not limitedto the electric motor 8 and may be a linear motor having a movingelement that reciprocally vibrates. Besides, a solenoid, a voice coilmotor or the like can also be used as such.

Alternatively, the vibrating element may be a permanent magnet 15 asshown as a sixth embodiment in FIG. 11A. In an appliance shown in FIG.11A, the bulge portions 7 a are respectively formed at positions of theouter layer 7B corresponding to the teeth 3 f, 3 i to be aligned and thepermanent magnet 15 is stored in each of these bulge portions 7 a.

This permanent magnet 15 can generate mechanical vibration by a magneticfield generated by magnetic field generating means arranged outside thedental mouthpiece 7. This magnetic field generating means isconstituted, for example, by a ring-shaped magnetic field generatingcoil (magnetic field generating means) 16 separate from the dentalmouthpiece 7 as shown in FIGS. 11B and 11C. This magnetic fieldgenerating coil 16 is arranged around the head of a user wearing thedental mouthpiece 7 while being separated from the user and generates amagnetic field for causing the permanent magnet 15 to generatemechanical vibration.

In this appliance, it is sufficient to build only the permanent magnet15 in the dental mouthpiece 7. This can reduce the size of the dentalmouthpiece 7 and reduce burdens on the user at the time of wearing thedental mouthpiece 7. This also increases the practical value of thedental mouthpiece 7 by making the dental mouthpiece 7 portable.

In the appliances according to the respective embodiments, there is apossibility of transmitting mechanical vibration not only to the teethto be aligned at the stored position of the vibrating element, but alsoto the other teeth 3 a to 3 n of the teeth 3, depending on the built-inposition of the vibrating element (electric motor 8 or permanent magnet15). This enables the treatment of the entire teeth 3 a to 3 n of theteeth 3.

The dental mouthpiece 7 of the foregoing embodiments is for impartingthe vibration force to the constant aligning force by being mounted onthe teeth 3 having the orthodontic wire 5 mounted thereon. However, thisdental mouthpiece 7 may be mounted on the teeth 3 having no orthodonticwire 5 mounted thereon and transmit only the vibration force by theelectric motor 8 to the teeth 3.

It is also possible to shape the dental mouthpiece 7 in such a manner asto apply a constant force (aligning force) to the teeth 3 g, 3 h to bealigned. Specifically, an instant teeth is elastic-deformedly mountedwith a dental mouthpiece having a targeted teeth shape (dentalmouthpiece having a shape different from the instant teeth shape) tothereby impart the elastic restoring force of the dental mouthpiece tothe instant teeth as an aligning force. In the case where a dentalmouthpiece is made from a high resilient and soft material, such dentalmouthpiece can be applied with a great elastic deformation. However, inthe case where a dental mouthpiece is made from a low resilient and hardmaterial, such dental mouthpiece cannot be applied with a great elasticdeformation, in other words, such dental mouthpiece cannot be used forteeth greatly different from the shape of the dental mouthpiece.However, such hard mouthpiece can form a precise shape, and impart adelicate aligning force to the teeth. Accordingly, there are provided amouthpiece which has a shape in agreement with a targeted teeth shape,and a mouthpiece which has an intermediate shape between an instantteeth shape and a targeted teeth shape.

Further, it may be possible to add a desired aligning shape to a mainbody of a dental mouthpiece. For example, a hard bulging portion 7 b isformed on the inner surface of an inner layer 7A in a dental mouthpiece7 shown in FIG. 8A, and a constant force (aligning force) is applied tothe teeth 3 g, 3 h to be aligned by a pressing force of the bulgingportion 7 b. It is also possible to join a hard bulging sheet 7 c withthe inner surface of the inner layer 7A as shown in FIG. 8B and to applya constant force (aligning force) to the teeth 3 g, 3 h to be aligned bythe pressing force of the bulging sheet 7 c. The position of the bulgingportion 7 b or the bulging sheet 7 c differs as a matter of fact if theteeth 3 g, 3 h to be aligned differ.

In the appliance whose outer layer 7B is directly mounted on the teeth 3as shown in FIGS. 7A and 7B, it is possible to integrally form a hardbulging portion on the inner surface of the outer layer 7B or to join ahard bulging sheet with this inner surface. If the inner layer 7A in theform of a rectangular piece shown in FIGS. 7A and 7B is hard itself, theconstant force (aligning force) can be applied to the teeth 3 g, 3 h tobe aligned by the pressing force of this inner layer 7A. This structureincreases the practical value of the appliance since the constantaligning force and the vibration force can be applied to the teeth 3 g,3 h to be aligned without mounting the orthodontic wire 5 on the teeth3.

FIG. 18 is a perspective view showing a producing apparatus 111 as oneexample of an apparatus for producing the dental mouthpiece 7. Thisproducing apparatus 111 is provided with a main body 114, a plurality ofsupporting columns 118 standing on the main body 114, a pair of sheetfixing devices 116, 117 supported on these supporting columns 118 insuch a manner as to be movable upward and downward along the supportingcolumns 118 and adapted to sandwich an EVA sheet 115 from above andbelow, and an electric heater 119 mounted on the supporting columns 118.The main body 114 has a stage 112 on which the dental cast 1 can beplaced, and has an unillustrated built-in pump for sucking air through amultitude of suction holes 113 formed in the stage 112.

FIG. 19 is a diagram showing a first example of a method for producingthe dental mouthpiece 7 using the aforementioned producing apparatus111. What should be first noted here is that the production of thedental mouthpiece 7 proceeds with the inner layer 7A and the outer layer7B mounted on the dental cast 1. The dental cast 1 is placed on thestage 112 of the producing apparatus 111 in Step S3. On the other hand,the EVA sheet 115 is sandwiched between the sheet fixing devices 116,117. Specifically, this sheet is heated and softened at a position nearthe electric heater 119 by the sheet fixing devices 116, 117 beinglifted up to this position along the supporting columns 118. After thesoftening, the EVA sheet 115 is gradually placed on the dental cast 1 asthe sheet fixing devices 116, 117 are lowered.

At this time, air is sucked through the air suction holes 113, therebygenerating an air flow to closely attach the EVA sheet 115 to the dentalcast 1. In order to enable this suction, a cut 1 a is made in the dentalcast 1. This suction enables precise dental impression. The principle ofsuch suction casting is only schematically shown in FIG. 21A. Theelectric heater 119 may also be lowered as the sheet fixing devices 116,117 are lowered. This downward movement of the electric heater 119enables continuous heating. Alternatively, as shown in FIG. 21B, thedental mouthpiece can be cast by pressurizing air around the EVA sheet115. This pressurization and the suction may be applied in combination.

The inner layer 7A is completed by the above casting. Up to Step S3,this method is the same as the conventional dental mouthpiece producingmethod. FIG. 19 is shown in FIGS. 2 to 11 on page 15 of “Not Only MouthGuard! Casting Machine Application Manual” (cowritten by Maeda andMatsuda, published by Quintessence Publisher).

What should be noted next is that a vibrating element such as theelectric motor 8 can be mounted in the inner layer 7A in Step S4 whilethe inner layer 7A is still hot. The material of the dental mouthpiece7, particularly the above EVA exhibits high viscosity in its moltenstate to such an extent as to be used also as a main ingredient ofso-called hot bond. Accordingly, the inner layer 7A having a hightemperature immediately after being cast in a half molten state in StepS3 as described above exhibits high viscosity until it is cooled. Anadhesive force given by the material of the inner layer 7A due to theremaining heat of the inner layer 7A can be utilized to mount thevibrating element. Specifically, it is sufficient to press the vibratingelement such as the electric motor 8 against the inner layer 7A whilethe inner layer 7A still has a high temperature. In this way, thevibrating element can be temporarily fixed without using special fixingmeans such as adhesive.

If the adhesive force by the viscosity of the inner layer 7A isinsufficient, such a shortage may be compensated for. For example, thevibrating element such as the electric motor 8 may be provided with aprojection and the inner layer 7A may be formed with a part engageablewith this projection, or the heated EVA may be poured into parts to befixed as auxiliary adhesive.

What should be further noted is that the vibrating element such as theelectric motor 8 can be sealed airtight in the inner layer 7A and theouter layer 7B in Step S5 shown in FIG. 19. Specifically, similar toStep S3, the heated EVA sheet 115 is placed on the inner layer 7A fittedwith the vibrating element as described above, and an actuator is causedto suck. In this way, the outer layer 7B is formed and the vibratingelement is sealed between the outer layer 7B and the inner layer 7A.

The softening temperature of the EVA sheet 115 as the material for theinner layer 7A and the outer layer 7B is set lower than the heatresistant temperature of the vibrating element. For example, if theelectric motor 8 having a heat resistant temperature of 100° C. is usedas the vibrating element, an EVA sheet having a softening point of 60 to70° C. is selected as the EVA sheet 115. The use of such an EVA sheetenables the EVA sheet to be directly mounted on the vibrating elementand the outer layer 7B to be cast by melting while enabling problemscaused by an excessive temperature rise of the vibrating element to besecurely prevented. “Bioplast” (product name) can be cited as an exampleof the EVA having such a low softening point.

If the heat resistant temperature of the vibrating element is evenhigher, materials having higher softening points can be used instead ofEVA materials. Specifically, polyolefin materials having softeningpoints of about 100° C. such as “MG-21” (product name) or PET-Ematerials having softening points between 100 and 200° C. such as“Duran” (product name) can be used.

After the dental mouthpiece 7 is fabricated in this way, EVA is peeledoff from a part of the outer layer 7B corresponding to lead wires 8 w ofthe electric motor 8, and the power feed cable 9 is connected with thelead wires 8 w in Step S6 of FIG. 19. Thereafter, in Step S7, an end ofan EVA tube 110 mounted on the power feed cable 9 is locally heated bymeans of a drier or the like to seal a connected part with the outerlayer 7B airtight, thereby completing the dental mouthpiece 7.

The method for producing the dental mouthpiece 7 according to the firstexample has an advantage of reducing operation steps since the dentalmouthpiece 7 can be fabricated with one dental impression. For example,a method shown in FIG. 12 requires two dental impressions. Specifically,after the inner layer 7A is competed, a second dental impression isperformed using the impression material with the electric motor 8 or itsdummy mounted in the inner layer 7A, and a plaster cast is formed again.After the EVA sheet 115 is placed on this plaster cast to form the outerlayer 7B, the inner layer 7A having the actual electric motor 8 mountedtherein and the outer layer 7B are welded.

Further, the method for producing the dental mouthpiece 7 according tothe first example enables the production of a high-quality dentalmouthpiece having high airtightness. Specifically, the inner layer 7Aand the EVA sheet for the outer layer 7B softened by being uniformly andentirely heated by the heat of the mounted EVA sheet for the outer layer7B become half molten to be naturally united. Thus, airtightness ishigher, for example, as compared to the case where the inner layer 7Aand the outer layer 7B already hardened are bonded to each other.Further, there are no inconveniences in the case of dental impressionusing a dummy such as problems of forming a clearance between the innerlayer 7A and the outer layer 7B and making it impossible to fit theinner layer 7A into the outer layer 7B. This enables the production of ahigh-quality dental mouthpiece.

FIG. 20 is a diagram showing a method for producing the dentalmouthpiece according to a second example. Since this producing method issimilar to the one according to the first example shown in FIG. 19,elements common to both examples are identified by common step numbersand are not described.

What should be noted in the producing method according to this secondexample is that the step of forming the outer layer 7B in Step S5 shownin FIG. 19 is changed to Step S5′ shown in FIG. 20. In Step S5′, thedental cast 1 having the inner layer 7A fitted with the vibratingelement such as the electric motor 8 mounted thereon is set in aninclined state on the stage 112 shown in FIG. 18. This inclination isfor preventing the dental cast 3 from being hidden from an air flow bythe electric motor 8. This inclination can be made by placing a rest 121as shown in FIG. 20 below a part of the dental cast 1 where the electricmotor 8 is mounted.

It is sufficient for the material for the inner layer 7A and the outerlayer 7B to have a softening point lower than the heat resistanttemperature of the vibrating element such as the electric motor 8 and tobe harmless to human bodies. The material is arbitrarily selected basedon hardness required for the respective pieces 7A, 7B after castingwithin such a range as to meet these conditions. However, it ispreferable to use a soft resin as the material. The use of the softresin has advantages of alleviating stimuli given to the teeth and gumsfrom the vibrating element, reducing loads given to the teeth and gums,mitigating discomfort such as pains, and improving wearing comfort ascompared to hard dental mouthpieces.

On the other hand, the use of a hard resin as the material hasadvantages of enabling the dental mouthpiece to be precisely cast, lessdeformation of the dental mouthpiece by the storage environment, andeasier quality maintenance. Accordingly, a hard resin may be used in thecase of attaching more importance to these advantages.

Further, the material for the inner layer 7A and the one for the outerlayer 7B may differ. For example, a dental mouthpiece having an overlaidstructure comprised of an inner layer 7A made of a soft resin and anoutput layer 7B made of a hard resin has advantages that the inner layer7A effectively alleviates impacts of a vibrating element to reduce loadson teeth to be aligned and gums, and the outer layer 7B made of the hardresin is easy to store because it is difficult to deform by theenvironment. Conversely, a dental mouthpiece having an overlaidstructure comprised of an inner layer 7A made of a hard resin and anoutput piece 7B made of a soft resin has advantages that the outer layer7B made of the soft resin absorbs impacts during sport and everyday lifeto effectively suppress damages of the dental mouthpiece and the teethon which the dental mouthpiece is mounted resulting from the impacts,and the inner layer 7A made of the hard resin enables production of adental mouthpiece having a precise inner shape. Further, this dentalmouthpiece can be more easily kept in shape than those entirely made ofthe soft resin.

Further, even in a dental mouthpiece made up of a single layer withouthaving an overlaid structure as above, it is possible to mixedly providesoft parts, i.e. those for weakly transmitting stimuli to the teeth 3and hard parts, i.e. those for strongly transmitting stimuli to theteeth 3.

Resins used for the material of the dental mouthpiece are:EVAs→polyolefins→polyesters and the like in a decreasing order ofsoftness. Even the same material has different compound ratios andhardnesses depending on products. Most EVAs are soft materials having ashore hardness of about 80 to 90 and widely used as the material forsoft dental mouthpieces. Conversely, most polyesters are hard materialsand widely used as the material for hard dental mouthpieces. There aresoft polyolefins and hard polyolefins depending on their compoundratios, but polyolefins are generally used as materials havinghardnesses between the EVAs and the polyesters.

Next, dental mouthpieces according to ninth to fifteenth embodiments aredescribed with reference to FIGS. 22 to 28. Each of the dentalmouthpieces according to these embodiments has dividing portions bydividing specified parts other than a part corresponding to teeth 3 g, 3h to be aligned. These dividing portions suppress the transmission ofmechanical vibration generated by a vibrating element so that themechanical vibration acts restrictedly on the teeth 3 g, 3 h to bealigned. Although an electric motor 8 is shown as the vibrating elementin FIGS. 22 to 28, the vibrating element may be other actuators, forexample, a permanent magnet.

FIG. 22 shows a dental mouthpiece 7-1 according to the ninth embodiment.The dividing portions of this dental mouthpiece 7-1 are cutout portions7 p. These cutout portions 7 p are formed by cutting out tooth crownportions of the dental mouthpiece 7-1 except at the part correspondingto the teeth 3 g, 3 h to be aligned. For example, elliptical cutouts aremade in the tooth crown portions for teeth 3 c to 3 e, 3 j to 3 l inFIG. 22. Dental root portions 7 q left in the dental mouthpiece 7-1 atthe parts where the cutout portions 7 p are formed integrally connectparts before and after the cutout portions 7 p.

FIG. 23 shows a dental mouthpiece 7-2 according to the tenth embodiment.The dividing portions of this dental mouthpiece 7-2 are also cutoutportions 7 p. These cutout portions 7 p are formed by cutting out toothroot portions of the dental mouthpiece 7-2 except at the partcorresponding to the teeth 3 g, 3 h to be aligned. For example,elliptical cutouts are made in the tooth root portions for the teeth 3 cto 3 e, 3 j to 3 l in FIG. 23. Tooth crown portions 7 r left in thedental mouthpiece 7-2 at the parts where the cutout portions 7 p areformed integrally connect parts before and after the cutout portions 7p.

In the dental mouthpieces 7-1, 7-2, the electric motor 8 for generatingmechanical vibration is stored at the part corresponding to the teeth 3g, 3 h to be aligned, and the cutout portions (dividing portions) 7 pfor suppressing the transmission of the mechanical vibration are formedin the parts other than the one corresponding to the teeth 3 g, 3 h tobe aligned. This enables the partial and precise application ofvibration to the teeth 3 g, 3 h to be aligned.

The cutout portions 7 p are formed by a post-processing of, e.g. cuttingoff the tooth crown portions or the tooth root portions of the dentalmouthpiece 7 shown in FIG. 1 using a cutter knife or the like.Accordingly, the dental mouthpieces 7-1, 7-2 having these cutoutportions 7 p can be easily produced. For example, a dental mouthpiecehaving the above cutout portions 7 p can be easily produced through thispost-processing from a dental mouthpiece actually worn by a user.

By connecting the parts before and after the cutout portions 7 p by thetooth root portions 7 q or the tooth crown portions 7 r left in thedental mouthpieces 7-1, 7-2, the shapes of the dental mouthpieces 7-1,7-2 can be so kept as to be entirely mountable on the teeth 3. Suchshapes facilitate an operation of mounting the dental mouthpieces 7-1,702 on the teeth 3, thereby enabling the electric motor 8 to beprecisely positioned at the part corresponding to the teeth 3 g, 3 h tobe aligned in the worn state.

FIG. 24 shows a dental mouthpiece 7-3 according to the eleventhembodiment. The dividing portions of this dental mouthpiece 7-2 are slitportions 7 s formed in parts of the dental mouthpiece 7-3 except a partcorresponding to the teeth 3 g, 3 h to be aligned. These slit portions 7s are formed in parts between the teeth 3 f, 3 g and between the teeth 3h, 3 i in FIG. 24, and parts before and after the respective slitportions 7 s are integrally connected. The right slit portions 7 s inFIG. 24 extend from a tooth root side toward a tooth crown side, whereasthe left slit portion 7 s extends from the tooth crown side toward thetooth root side. In the present invention, the directions of these slitportions are not limited.

The dental mouthpiece 7-3 according to this eleventh embodiment canachieve functions and effects similar to those of the dental mouthpieces7-1, 7-2.

FIG. 25 shows a dental mouthpiece 7-4 according to the twelfthembodiment. The dividing portions of this dental mouthpiece 7-4 are cutportions 7 t formed by cutting parts except at the one corresponding tothe teeth 3 g, 3 h to be aligned. In FIG. 25, the cut portions 7 t areformed by making cuts between the teeth 3 f, 3 g and between 3 h, 3 i,and parts before and after the respective cut portions 7 t areintegrally connected, for example, by means of wires 21 or the likeinsert-cast in the dental mouthpiece 7-4.

The dental mouthpiece 7-4 according to this twelfth embodiment can alsoachieve functions and effects similar to those of the dental mouthpieces7-1, 7-2 and 7-3.

FIG. 26 shows a dental mouthpiece 7-5 according to the thirteenthembodiment. The dividing portions of this dental mouthpiece 7-5 are softportions 7 u made of a soft material. In this dental mouthpiece 7-5, thepart corresponding to the teeth 3 g, 3 h to be aligned is made of anordinary mouthpiece material, whereas the other parts (parts hatchedwith oblique lines in FIG. 26) are made of the soft material less likelyto transmit the mechanical vibration to form the soft portions 7 u.

The dental mouthpiece 7-5 according to this thirteenth embodiment canalso achieve functions and effects similar to those of the dentalmouthpieces 7-1, 7-2, 7-3 and 7-4. Further, the dental mouthpiece 7-5has an advantage of having no clearances such as the cutout portions 7 pand the slit portions 7 s.

FIG. 27 shows a dental mouthpiece 7-6 according to the fourteenthembodiment. The dividing portions of this dental mouthpiece 7-6 arecutoff portions 7 v shown by chain double-dashed line. These cutoffportions 7 v are formed by cutting off parts of the dental mouthpiece7-4 at parts at least except the one corresponding to the teeth 3 g, 3 hto be aligned (teeth 3 f, 3 i near the teeth 3 g, 3 h to be aligned arealso included in FIG. 27). Accordingly, this dental mouthpiece 7-6 ismounted only on the teeth 3 g, 3 h to be aligned (or on the teeth 3 g, 3h to be aligned and their neighboring teeth 3 f, 3 i).

The dental mouthpiece 7-6 according to this fourteenth embodiment canalso achieve functions and effects similar to those of the dentalmouthpieces 7-1, 7-2, 7-3, 7-4 and 7-5.

The dental mouthpiece 7-6 may be mounted on only a single tooth. Forexample, the dental mouthpiece 7-6 may be so shaped and constructed asto be mounted only on one tooth 3 g or 3 h to be aligned.

In the case where all the teeth 3 a to 3 n are to be aligned, the dentalmouthpiece 7-6 may be individually mounted on each of the teeth 3 a to 3n to be aligned. In such a case, the dental mouthpieces 7-6 can besuccessively detached from the teeth for which orthodontic treatment hasbeen finished. Alternatively, the dental mouthpiece 7-6 can besuccessively mounted and detached. For example, a treatment is firstconducted by mounting the dental mouthpiece 7-6 on the teeth at the backside, and the dental mouthpiece 7-6 is detached after the orthodontictreatment is finished. A subsequent treatment is conducted by mountingthe dental mouthpiece 7-6 on the teeth before the already treated teeth.In this way, the dental mouthpiece 7-6 can be successively mounted onand detached from the teeth from the posterior tooth side toward thefront tooth side.

FIG. 28 shows a dental mouthpiece 7-7 according to the fifteenthembodiment. The dividing portions of this dental mouthpiece 7-7 arecutoff portions 7 v (see chain double-dashed line) formed by cutting offthe dental mouthpiece 7-7 except at parts corresponding to the teeth 3c, 3 d to be aligned, the teeth 3 g, 3 h to be aligned and the teeth 3k, 3 l to be aligned. Accordingly, the dental mouthpiece 7-7 is mountedonly on the teeth 3 c, 3 d to be aligned, the teeth 3 g, 3 h to bealigned and the teeth 3 k, 3 l to be aligned.

The dental mouthpiece 7-7 according to this fifteenth embodiment canalso achieve functions and effects similar to those of the dentalmouthpieces 7-1, 7-2, 7-3, 7-4, 7-5 and 7-6.

The dental mouthpiece 7-7 is divided into a plurality of (three in thisexample) mutually independent segments by the cutoff portions (dividingportions) 7 v. In this construction, the direction and intensity of thevibration to be applied can be changed for each segment, which enablesadaptations to various teethes and bites. One or more vibrating elements(electric motor(s) 8 and/or permanent magnet(s) 15) can be stored foreach segment. In the case of storing a plurality of vibrating elements,the kind (e.g. electric motor or permanent magnet) of the vibratingelements, the directions and intensities of the vibration can bedifferent from each other.

Since the parts before and after the divided sections are integrallyconnected to each other in the dental mouthpieces 7-1 to 7-4 accordingto the ninth to twelfth embodiments, each dental mouthpiece is entirelyformed by a single segment, but the parts before and after the dividingportions can be seen as the mutually independent segments since therespective dividing portions suppress the transmission of the mechanicalvibration. Accordingly, in a construction in which vibrating elementssuch as the electric motors 8 are stored in the segments before andafter the dividing portions similar to the dental mouthpiece 7-7according to the fifteenth embodiment, the direction and intensity ofthe vibration to be applied can be changed for each segment, therebyenabling adaptations to various teethes and bites. Further, it is alsopossible to store one or more vibrating elements in each segment.

Since the dividing portions are the cutout portions 7 p, the slitportions 7 s or the cut portions 7 t in the dental mouthpiece 7-1 to 7-4according to the ninth to twelfth embodiments, the segments unnecessaryfor the treatment by a treatment plan or the segments having used forthe already finished orthodontic treatment can be locally removed bybeing cut at the dividing portions if the vibrating elements are storedin the respective segments before and after the dividing portions. It ismore preferable to have such a construction that the parts cut at thedividing portions can be reconnected. This construction can be realized,for example, by mounting fittings attachable to and detachable from eachother, magnetic elements attracting each other, adhesive materials orthe like at the cut positions.

The dental mouthpieces 7-1 to 7-7 according to the above embodiments arenot limited to those having an inner and outer overlaid structurecomprised of the inner layer 7A and the outer layer 7B. In short, it issufficient to store the vibrating element at the part corresponding tothe tooth to be aligned. For example, a casing storing the electricmotor 8, a button battery 11′ and the permanent magnet 15 may be joinedwith a main body of a dental mouthpiece having a normal single-layerstructure at a position near the tooth to be aligned.

FIG. 29 is a perspective view showing a state where a dental mouthpieceaccording to a sixteenth embodiment of the invention is mounted on thelower dental arch of a user, and FIG. 30 is a section along the line30-30 in FIG. 29.

The dental mouthpiece 7 according to this embodiment is characterized bythe shape of a storage space of a vibrating element storing portion.This storage space is so shaped as to provide the vibrating element witha play permitting the vibrating element itself to move in the storagespace.

In FIG. 29, an outer layer 7B constituting the dental mouthpiece 7 isformed with a bulge portion 7 a similar to the first embodiment, and anelectric motor 8 as a vibrating element is stored in this bulge portion7 a. This electric motor 8 has a cylindrical shape and is stored in thebulge portion 7 a in such a posture that a direction of the central axisthereof is a horizontal direction (transverse direction) along the teeth3.

On the other hand, a storage space 7 b formed in the bulge portion 7 a,i.e. a space for storing the electric motor 8 has a cylindrical shapewhose cross section normal to longitudinal direction has an ellipticalshape longer in horizontal direction. Accordingly, the shape of thestorage space 7 b is larger than the outer shape of the electric motor 8and provides a clearance or a play extending in horizontal direction(inward and outward directions of the buccal cavity).

The storage space 7 a according to this embodiment permits the electricmotor 8 to be displaced along horizontal direction (inward and outwarddirections of the buccal cavity) without completely restraining theelectric motor 8, i.e. provides the electric motor 8 with a play.Accordingly, a vibration load generated by the electric motor 8 as thevibrating element causes the electric motor 8 itself to vibrate alongthe direction of the above clearance (horizontal direction) and tocollide with the wall surface defining the storage space 7 b. Thisvibration load amplifies vibration to be applied to the teeth 3 of theuser wearing the dental mouthpiece 7, thereby further improving theorthodontic effect by that much.

FIG. 32 are graphs showing an experiment result obtained by theinventors of the present application. FIG. 32A shows the amplitude ofvibration to be applied to the teeth 3 g, 3 h to be aligned from adental mouthpiece 7 whose storage space 7 b has a shape equal to theouter shape of the electric motor 8, i.e. a dental mouthpiece 7 in whichthe electric motor 8 is completely restrained in the storage space 7 asa reference example, and FIG. 32B shows the amplitude of vibration inthe case where a play is provided in the storage space 7 b as shown inFIG. 29.

FIG. 32A shows that regular vibration of about 200 Hz is applied with avibration load of about 30 g by the eccentric weight of the electricmotor 8 in the case where the electric motor 8 is completely restrainedin the storage space 7 b. On the other hand, FIG. 32B shows thatvibration is irregular, but the vibration load is increased (doubled) upto about 60 g in the case where there is the play.

In this embodiment, the direction of the play (direction of theclearance) coincides with a direction conforming to the aligningdirection of the teeth 3 g, 3 h to be aligned in the storage space 7 b.This largely contributes to the promotion of the orthodontic effect.

For example, in the case of retracting a tooth sticking out forward andin the case of pulling a retracted tooth forward, the direction of theclearance may coincide with forward and backward directions. Further, inthe case of aligning a twisted tooth, the direction of the clearance maycoincide with a direction in which the tooth should be twisted back andwhich is substantially normal to the tooth surface. In an example shownin FIG. 33, the direction of the clearance is set to be substantiallynormal to the right half of the tooth surface of the tooth 3 g to bealigned, which is supported to be twisted in counterclockwise directionwhen viewed from above.

A vibration effect utilizing such a clearance enables the application ofthe vibration load having high directivity to the teeth. For example,even if a vibrating element exemplified by the electric motor 8 andhaving high directivity cannot be used in light of cost and size and,instead, an inexpensive and small-sized rotary motor or vibration motorhas to be used, sufficient stimuli can be given to promote theorthodontic effect by applying a vibration load having high directivityto the tooth to be aligned.

A seventeenth embodiment of the present invention is described withreference to FIG. 34. FIG. 34 is a perspective view showing a statewhere a dental mouthpiece 7′ according to one embodiment of the presentinvention is mounted on a dental cast 1 of a user. The dental mouthpiece7′ of this embodiment includes a lower layer 71 corresponding to adental cast 1A of the lower dental arch, an upper layer 72 correspondingto a dental cast 1B of the upper dental arch, connecting members 251,252 connecting both layers 71, 72 at positions distanced from teeth tobe aligned, and electric motors 8 as one example of a vibrating element.The upper layer 72 is mountable on the upper teeth, and the lower layer71 is mountable on the lower teeth.

The lower layer 71 and the upper layer 72 of this dental mouthpiece 7′are both produced using an apparatus equivalent to the producingapparatus 111 shown in FIG. 18 by a method equivalent to the producingmethod shown in FIG. 19. Thereafter, the connecting members 251, 252 areformed in the following manner.

First, the lower layer 71 and the upper layer 72 produced as above aremounted on corresponding dental casts 1A, 1B of the dental cast 1 havingthe bite thereof adjusted. Subsequently, EVA columns having the oppositeends thereof heated to be molten are caused to stand at specifiedpositions of the lower layer 71 with both dental casts 1A, 1B opened,and then the dental casts 1A, 1B are closed up to a specified angle. Inthis way, the ends of the EVA columns at, an opposite side come intocontact with the upper layer 72. The EVA columns become the connectingmembers 251, 252 connecting both layers 71, 72 by being cooled in thisstate, whereby a pair of upper and lower dental mouthpieces 7′ iscompleted.

The connecting members 251, 252 are provided at the positions distancedfrom the teeth to be aligned between the upper and lower layers 72, 71.For example, if the teeth to be aligned are left and right molar teeth(e.g. teeth 3 a to 3 d and 3 k to 3 n in the teeth shown in FIG. 1) andthe vibrating elements such as the electric motors 8 are built in thedental mouthpiece 7′ at positions near these teeth, the connectingmembers 251, 252 may be formed at the positions near the front teeth(central incisors) 3 g, 3 h as shown in FIG. 34. Alternatively, only asingle connecting member 250 may be formed as in a dental mouthpiece 7″shown as an eighteenth embodiment in FIG. 35. On the other hand, if theteeth to be aligned are front teeth (lateral incisors) 3 f, 3 i andfront teeth (canine teeth) 3 e, 3 j shown in FIG. 1 and the vibratingelement such as the electric motor 8 is built in at the position shownin FIG. 2, the connecting members may be formed at positions near theleft and right posterior teeth (e.g. at positions of the teeth 3 c, 3 dand teeth 3 k, 3 l of FIG. 1 or at their neighboring positions).

In a dental mouthpiece 7′″ shown as a nineteenth embodiment in FIG. 36,the left and right connecting members (only left connecting member 251is shown in FIG. 36) are provided at positions more toward the posteriorteeth than the molar teeth. The connecting members provided at suchpositions enable no load caused by the bite to be applied to any of thefront teeth (central incisors) 3 g, 3 h, the front teeth (lateralincisors) 3 f, 3 i, the front teeth (canine teeth) 3 e, 3 j, the molarteeth 3 a to 3 d, 3 k to 3 n as shown in FIG. 1. In other words, theopen state can be kept. Such a dental mouthpiece is suitable in the caseof aligning the entire teeth.

In the dental mouthpieces including the respective connecting members,the biting state (bite force and biting surfaces) of the upper layer 72and the lower layer 71 can be kept constant at the position(s) where thevibrating element such as the electric motor 8 is provided. Thisprevents a change in the vibration transmission mode caused by anunconscious behavior of the user to bite the electric motor 8 or itsneighboring part. In other words, this eliminates the need for the userto make an effort to keep the dental mouthpiece open, whereby a goodorthodontic effect can be obtained by continuing to apply specifiedvibration to the teeth to be aligned while reducing burdens on the user.

The inner surface form of the dental mouthpiece according to the presentinvention is preferably in conformity with the dental cast 1 of the userwearing braces including the orthodontic wire 5 and the brackets 4. Thedental mouthpiece reflecting the shape of the braces can be mounted onthe teeth wearing the braces, and can be used in combination with thebraces.

FIG. 37 is a diagram showing a method for producing such a dentalmouthpiece. What should be noted here is that a dental impression isobtained with the brackets 4 and the orthodontic wire 5 mounted on thedental cast 1 (Step S1) and the dental cast 1 is completed (Step S2).Thereafter, dental wax 260 is filled into clearances in parts of thedental cast 1 corresponding to the brackets 4 and the orthodontic wire 5to thereby eliminate unevenness in Step S11. So-called “paraffin wax” orthe like can be used as the dental wax. This material is solid at normaltemperature, and is used in liquid state by being heated and moltenusing an alcohol lamp or the like.

This method reduces burdens on the user as compared to the methodaccording to which the wax is used upon obtaining the dental impressionin Step S1, i.e. the method according to which the dental impression isobtained after nontoxic wax or the like that can be washed away withwater is filled into clearances of the brackets 4 and the orthodonticwire 5 with the user wearing the brackets 4 and the orthodontic wire 5.

Further, in Step S12, the inner surface form of the impression material6 obtained using silicon corresponds to an envelope of the outer shapeof the braces including the bracket 4 and the orthodontic wire 5. Thisshape is such a shape capable of avoiding the interference of theunevenness of the braces with the inner surface of the dental mouthpieceto be cast, and a clearance is defined between the inner surface of theimpression material and the buccal surface of the teeth 3. Thereafter,plaster is poured into the impression material 6 and taken out afterbeing hardened, whereby a dental cast 1′ actually used for theproduction of the dental mouthpiece 7 is completed. Processes after StepS13 are equivalent to the method shown in FIG. 19.

The inner surface form of the inner layer 7A of the dental mouthpiece 7thus produced conforms to the dental cast 1 of the user wearing thebraces including the orthodontic wire 5 and the brackets 4. In otherwords, since the inner surface of this inner layer 7 reflects the shapeof the braces, the dental mouthpiece 7 is mountable on these braces,which enables the simultaneous use of the dental mouthpiece 7 and thebraces.

Further, since the inner surface form of the inner layer 7A correspondsto the shape of the braces including the orthodontic wire 5 and thebrackets 4 after having the unevenness reduced and reflects this unevenshape as clearances, the interference of the sharp orthodontic wire 5and the brackets 4 with the inner layer 7A can be reduced. This preventsthe braces from being displaced or coming off and the dental mouthpiece7 from being damaged when the braces and dental mouthpiece 7 are mountedand detached.

FIG. 38 is a perspective view showing a state where a dental mouthpiece7 according to a twentieth embodiment of the present invention ismounted on a user's lower dental arch, FIG. 39 is a perspective view ofa dental cast 1 of the user's lower dental arch and FIG. 40 is a sectionalong the line 40-40 in FIG. 38.

The orthodontic appliance according to this embodiment is characterizedby including a flexible board 2 on which an electric motor 8 as avibrating element is mounted and incorporating both the electric motor 8and the flexible board 2 into the dental mouthpiece 7.

FIG. 41 is an exploded perspective view showing the construction of theelectric motor 8 and the flexible board 2, and FIG. 42 is a section ofthe dental mouthpiece 7 having these built therein.

The electric motor 8 includes a motor main body 8 a, a rotary shaft 8 band an eccentric weight 8 c mounted on this rotary shaft 8 b, andgenerates mechanical vibration of the rotations of the rotary shaft 8 band the eccentric weight 8 c. The electric motor 8 is of the unpackedtype having the eccentric weight 8 c thereof exposed to the outside.Accordingly, if this electric motor 8 is built in the dental mouthpiece7 together with the flexible board 2 as it is, the eccentric weight 8 ctouches inner surface of the dental mouthpiece 7 (e.g. inner surface ofa bulge portion 7 a for the storage of the vibrating element shown inFIG. 38) and the like, and this touch might hinder the rotation of theeccentric weight 8 c.

In order to prevent this inconvenience, a cover member 8 d is providedon the flexible board 2. This cover member 8 d is made of metal or thelike, has a semicylindrical shape with a closed top and covers theeccentric weight 8 c in such a manner as to ensure a space for therotation of the eccentric weight 8 c.

The flexible board 2 is in the form of a strip extending in a directionalong the teeth 3 as shown in FIG. 38 and has a circuit for introducingan electric power to the motor main body 8 a. Specifically, thisflexible board 2 is formed with a pair of wiring patterns 2 a; 2 bextending in the longitudinal direction thereof, and lands 2 c used tosolder terminals 8 e provided on the motor main body 8 a are formed at aplurality of positions of the respective wiring patterns 2 a, 2 b.

Even if this flexible board 2 is formed to have a standardized shape, itcan be commonly used for a plurality of users whose teeth to be aligneddiffer from each other. In other words, even if the teeth to be aligneddiffer from user to user, the use of the flexible board 2 is enabled byselecting the lands 2 c at positions corresponding to the teeth to bealigned (e.g. teeth 3 g, 3 h to be aligned shown in FIG. 38) as those towhich the terminals 8 e of the motor main body 8 a are soldered. It isalso possible to mount a plurality of electric motors 8 on one flexibleboard and to simultaneously drive them.

The enlargement of the lands 2 c of the flexible board 2 strengthens thesoldering of the terminals 8 e to the lands 2 c. This soldering has aremarkably lower probability of breaking than a power feed path formedby a lead wire directly drawn out from the electric motor 8, i.e. formsa power feed path having higher reliability. Further, the use of theflexible board 2 neither damages the dental mouthpiece 7 nor hurts thebuccal cavity.

The electric motor 8 may be either a direct-current (DC) motor or analternating-current (AC) motor. In the former case, the intensity andcycle of the vibration can be made adjustable by feeding a power from abattery via a switch and a variable resistor. The rotating speed of themotor main body 8 a, i.e. vibration frequency (number of vibration) ofthe motor main body 8 a is preferably about several Hz to several 100Hz.

In order to mount the cover member 8 d, a plurality of locking holes 2 daligned in the longitudinal direction of the flexible board 2 areperforated at each of the opposite lateral edges of the flexible board2. On the other hand, projections 8 f are formed at the bottom of thecover member 8 d and fittable into arbitrary locking holes 2 d. Bychanging the locking holes 2 d into which the projections 8 f arefitted, the arranged position of the cover member 8 d on the flexibleboard 2 is changed. Accordingly, regardless of to which lands the motormain body 8 a is soldered, the cover member 8 d can be temporarily fixedat such a position as to cover the eccentric weight 8 c by acorresponding selection of the suitable locking holes 2 d into which theprojections 8 f of the cover member 8 d are to be fitted. If the mountposition of the motor main body 8 a on the flexible board 2 is fixed,the lands 2 c and the locking holes 2 d may be provided only at oneposition.

The flexible board 2 having the electric motor 8 and the cover member 8d mounted thereon is sealed between the inner layer 7A and the outerlayer 7B of the dental mouthpiece 7 in the same manner as describedabove, and the cover member 8 d is fixed to the flexible board 2.Accordingly, even if the electric motor 8 of the unpacked type is used,the normal operation thereof can be guaranteed.

A board side connector 6 a for the connection of the flexible board 2and an external circuit of the dental mouthpiece 7 is provided at oneend of the flexible board 2 with respect to longitudinal direction. Forexample, a two-pin connector produced by Japanese Solderless TerminalsManufacturing Co., Ltd. (JST Mfg. Co., Ltd.) is used as this board sideconnector 6 a. Terminals of this board side connector 6 a are solderedto lands 2 e formed at ends of the wiring patterns 2 a, 2 b at one side.Besides the electric motor 8, a control circuit and a power sourcetherefor may be mounted on the flexible board 2. In the case of mountingthe control circuit, the board side connector 6 a may further include apin for the transmission of a control signal. Further, in the case ofmounting the power source, the connector 6 a may be used for the on-offcontrol and power control.

On the other hand, a lead-wire side connector 6 b is provided at ends ofpower feed cables (lead wires) 9 to be drawn out, and is connected withthe board side connector 6 a. These lead-wire side connector 6 b andboard side connector 6 a form the connector 6 electrically connectingthe flexible board 2 and the power feed cables 9.

The use of the connector 6 facilitates a wiring operation between theflexible board 2 and the external circuit. Specifically, as described indetail later, the wiring operation with the outside is performed only byexposing a part of the sealed flexible board 2 corresponding to theconnector 6 a, connecting the lead-wire side connector 6 b with theexposed connector 6 a and sealing the exposed part again. This methodremarkably simplifies the wiring operation as compared to a methodincluding steps of exposing the wiring patterns 2 a, 2 b of the sealedflexible board 2 and sealing the exposed parts again after the powerfeed wires 9 to be drawn out are soldered.

A direction in which the power feed cables 9 are drawn out by thisconnector 6 is preferably perpendicular to the flexible board 2, i.e.perpendicular to the tooth surface in light of wearing comfort and theconnecting operation of the connectors 6 a, 6 b. Normally, the connector6 is set at a position corresponding to the front teeth 3 g, 3 h in viewof facilitation to take the lead wires out of the buccal cavity. If theteeth to be aligned are the front teeth 3 g, 3 h, the position of theconnector 6 needs to be changed to a proximate position (e.g. positioncorresponding to the tooth 3 i in FIG. 38). Such a change can beaccomplished by displacing the built-in position of the flexible board 2in the dental mouthpiece 7. An unnecessary part of the flexible board 2may be built in the dental mouthpiece 7 while being folded or may be cutoff.

The power feed cables 9 are covered by an EVA tube 280 made of the samematerial as the dental mouthpiece 7. The use of this EVA tube 280enables the drawn-out portions of the power feed cables 9 to the outsideto be also sealed airtight. Specifically, the airtight sealing of thedrawn-out portions of the power feed cables 9 to the outside of thedental mouthpiece 7 is realized by a method including a step of exposinga part of the board side connector 6 sealed in the dental mouthpiece 7as described above, a step of connecting the lead-wire side connector 6b with this connector 6 a and a step of uniting an end 282 of the EVAtube 280 with a part exposed for the connection of the two connectors 6a, 6 b, for example, by melting.

If the connection of the flexible board 2 and the external circuit ofthe dental mouthpiece 7 is unnecessary, the connector 6 can be omitted.In such a case, no control is necessary from the external circuit tostrengthen or weaken the vibration. An exemplary case is such that thepower source and the control circuit are also mounted on the flexibleboard 2 as described above and the electric motor 8 can be turned on andoff through the operation of a push-push switch at a thinned part of theouter layer 7B.

If the flexible board 2 is built in the dental mouthpiece 7, theexternal appearance of the appliance is determined only by the dentalmouthpiece 7. Since the power feed cables do not touch the buccal cavitywith this appliance, electrical safety can be ensured and an improvementin wearing comfort can be expected. Further, the entire appliance iscompact and convenient to carry around, and the practical value thereofis high.

FIG. 43 is a diagram showing a method for producing the dentalmouthpiece 7 according to this embodiment. Up to the completion of theinner layer 7A (Step S3), this method is the same as the dentalmouthpiece producing method shown in FIG. 19.

After the completion of the inner layer 7A, the flexible board 2 havingthe electric motor 8 and the connector 6 a mounted thereon is attachedonto the inner layer 7A while the inner layer 7A is still hot. Thematerial of the dental mouthpiece 7, particularly the EVA, has highviscosity when being molten to such an extent as to be used as a mainraw material of so-called hot bond. Accordingly, the inner layer 7Aimmediately after being cast from the half molten EVA in Step S3 stillhas heat and exhibits high viscosity until being cooled. The flexibleboard 2 can be temporarily fixed without particularly using fixing meanssuch as adhesive only by pressing the flexible board 2 against the innerlayer 7A utilizing an adhesive force of the material of the inner layer7A given by the remaining heat of the inner layer 7A.

In Step S15, the outer layer 7B is formed by placing the heated EVAsheet on the inner layer 7A having the flexible board 2 attached theretoas described above as in Step S3 and applying air suction. At this time,the flexible board 2, the electric motor 8 and the connector 6 a aresealed airtight between the inner layer 7A and the outer layer 7B.

In Step S16, the EVA forming the outer layer 7B is stripped at a partcorresponding to the board side connector 6 a in the dental mouthpiece 7formed in this way, and the lead-wire side connector 6 b is connectedwith the connector 6 a. In Step S17, the end portion 282 of the EVA tube280 mounted on the power feed cables 9 are connected at a suitableposition of the outer layer 7B by being locally heated using a drier orthe like, and this connected part is sealed airtight. In this way, thedental mouthpiece is completed.

In order to easily insert the power feed cables 9 into the EVA tube 280,the end portion 282 of the tube 280 at an insertion side is preprocessedto be widened as shown in FIGS. 41 and 42. This widening process isrealized, for example, by a method including a step of mounting atubular body having a heat insulating property on the tube 280 andpulling only the end portion 282 from this tubular body, and a step ofsoftening the pulled-out end portion 282 by locally heating it using adrier or the like and inserting a conical body into the end portion 282to deform the end portion 282 into a shape conforming to the outercircumferential surface of this conic body. The power feed cables 9connected with the lead-wire side connector 6 b are inserted for theconnection in Step S16 with the tubular body mounted thereon. Thisenables complete waterproofing from the dental mouthpiece 7 to thepulled-out portions of the power feed cables 9.

FIG. 44 is a plan view of a flexible board 2′ used in an orthodonticappliance according a twenty first embodiment of the present invention.This flexible board 2′ is similar to the flexible board 2, and portionsof both equivalent to each other are identified by the same referencenumerals and are not described.

What should be noted in this flexible board 2′ is that the board sideconnector 6 a is mounted at a longitudinal middle position of theflexible board 2′ and the flexible board 2′ extends toward the oppositesides in directions along the teeth 3 with this connector 6 a as acenter. Accordingly, this flexible board 2′ is suitable for theorthodontic alignment of the molar teeth at the opposite sides since theboard side connector 6 a is mounted at the position corresponding to thefront teeth if the flexible board 2′ is used as it is.

This flexible board 2′ is characterized by perforation 2 f formed at oneside of the connector 6 a to facilitate the separation of the flexibleboard 2′. In the flexible board 2′ separated at the perforation 2 f, theboard side connector 6 a is located at an end with respect tolongitudinal direction. This enables the position where the power feedcables 9 are drawn out from the board side connector 6 a to be locatedat the position of the molar teeth (back side) similar to theaforementioned flexible board 2, and enables the use of the flexibleboard 2′ for the orthodontic alignment of the front teeth.

The opposite ends of the flexible board 2′ may be suitably cut off inconformity with the size of a user's mouth. This enables the use of thecommon flexible board 2′ regardless of tooth (teeth) to be aligned andthe size of the user's mouth.

According to the present invention, the vibrating element (e.g. electricmotor 8) is not necessarily fixed to the lands of the flexible board asdescribed above. For example, the vibrating element may be slidablymounted on the flexible board. This sliding movement enables thepositions of the vibrating element on the flexible board to be changed.

As described above, the present invention is directed to an orthodonticappliance for aligning teeth including a tooth to be aligned, theappliance comprising a vibrating element for generating mechanicalvibration and applying this vibration to the tooth to be aligned, and adental mouthpiece having the vibrating element built therein andmountable on the teeth with the vibrating element built therein. Sincethe vibrating element for generating mechanical vibration (mechanicalstimuli) is built in the dental mouthpiece to be mounted on the teeth inthis appliance, the vibrating element can efficiently apply vibration tothe tooth to be aligned. Further, the storage of the vibrating elementin the dental mouthpiece enables a treatment to be easily and safelycontinued at any desired time, for example, at home without going to adental clinic.

It is preferable that the dental mouthpiece includes an inner layer andan outer layer to be superimposed on the outer side of the inner layer;and that a vibrating element storing portion for storing the vibratingelement is formed between the Inner layer and the outer layer. Thisconstruction facilitates the storage of the vibrating element into thedental mouthpiece. Since the mechanical vibration of the vibratingelement is transmitted to the tooth to be aligned via the superimposedpart of the dental mouthpiece having an overlaid structure, thisvibration can be more softly transmitted as compared to the case wheremechanical vibration is directly transmitted to the tooth to be aligned.Further, the dental mouthpiece is water-washable and, thus, hygienic ifthe vibrating element is hermetically stored in the dental mouthpiece.

Specifically, it is preferable that the outer layer includes an outwardprojecting bulge portion; and that the vibrating element is storedbetween the inner side of the bulge portion and the outer side of theinner layer. This structure enables the storage of the vibrating elementinto the dental mouthpiece without enlarging the entire dentalmouthpiece.

The vibrating element storing portion is more preferably formed at apart of the dental mouthpiece corresponding to the tooth to be aligned.

For example, a motor is preferably used as the vibrating element. Inorder to make this vibrating element more inexpensive, the motorpreferably includes an eccentric rotary portion rotatable about aspecified axis and having a center of gravity at a position deviatedfrom this axis. For example, this eccentric rotary portion preferablyincludes a rotary shaft and an eccentric weight mounted on this rotaryshaft such that the center of gravity thereof is deviated from thecenter of the rotary shaft and adapted to generate mechanical vibrationby rotating together with the rotary shaft.

The vibrating element may be a linear motor having a moving element thatreciprocally vibrates.

If the appliance according to the present invention further comprises abattery as a direct-current power source and the motor is a DC motordriven by the direct-current power source and electrically connectedwith the battery, a treatment can be made, for example, outdoors.

Further, if the battery is stored in the vibrating element storingportion together with the motor, the wearing comfort becomes improvedbecause a cable does not expose out of the mouth, and carrying of theappliance is more convenient.

The vibrating element is more preferably built in the dental mouthpiecein such an orientation that the direction of the vibration generated bythe vibrating element is substantially normal to the teeth. This canimprove vibration transmission efficiency.

The vibrating element may be a permanent magnet for generatingmechanical vibration in response to a magnetic field generated bymagnetic field generating means arranged outside the dental mouthpiece.The use of this permanent magnet makes the entire appliance smaller.

The dental mouthpiece may be so shaped as to be mountable on bracesmounted on the teeth to align the tooth to be aligned or may be soshaped as to apply an aligning force to the tooth to be aligned.

The former dental mouthpiece preferably has an inner surface formconforming to the dental cast of the user wearing the braces. Since theinner surface form of this dental mouthpiece reflects the shape of thebraces, the dental mouthpiece can be mounted on the braces. Thisrealizes the simultaneous use of the braces and the dental mouthpiece.

The inner surface form of such a dental mouthpiece is preferably a shapecorresponding to an envelope of the outer shape of the braces andcapable of avoiding the interference of the unevenness of the braceswith the inner surface of the dental mouthpiece. Such a shape has thefollowing advantages.

-   -   Stimuli from the vibrating element to the teeth are alleviated        to prevent the gums to be hurt by the stimuli.    -   Wearing comfort is improved.    -   The production of the dental mouthpiece is facilitated.    -   Damages of the gums by the edges and the like of the dental        mouthpiece can be prevented.

The dental mouthpiece may be so shaped as to be mountable on the entireteeth or may be so shaped as to be mountable on a part of the teeth. Theformer shape enables the positional relationship between the tooth to bealigned and the vibrating element to be more precisely set. The lattershape can make the dental mouthpiece smaller.

Further, it is more preferable that the dental mouthpiece includes adividing portion at a part thereof except at the one corresponding tothe tooth to be aligned; and that this divided portion suppresses thetransmission of mechanical vibration so that the mechanical vibrationgenerated by the vibrating element acts restrictedly on the partincluding the tooth to be aligned.

This construction enables the vibration to be restrictedly applied tothe tooth to be aligned.

The dental mouthpiece including the dividing portion preferablyincludes, for example, any one of the following constructions in orderto facilitate the production thereof.

a) The dividing portion of the dental mouthpiece is a cutout portionformed by cutting out either a tooth root portion or a tooth crownportion of the dental mouthpiece except at the tooth to be aligned, andthe other part integrally connect parts of the dental mouthpiece beforeand after the cutout portion.

b) The dividing portion of the dental mouthpiece is a slit portionformed in a part of the dental mouthpiece except at the tooth to bealigned, and parts of the dental mouthpiece before and after this slitportion are connected to each other.

c) The dividing portion of the dental mouthpiece is a cut portion formedby cutting a part of the dental mouthpiece except at the tooth to bealigned, and parts of the dental mouthpiece before and after this cutportion are connected via a member separate from the one forming the cutportion.

d) The dividing portion of the dental mouthpiece is a cutoff portionformed by cutting off a part of the dental mouthpiece except at thetooth to be aligned, and this cutoff portion is defined in such aposition that the dental mouthpiece has a shape fittable for only thetooth to be aligned.

e) The dividing portion of the dental mouthpiece is a cutout portionformed by cutting out either a tooth root portion or a tooth crownportion of the dental mouthpiece except at the tooth to be aligned, andparts of the dental mouthpiece before and after the cutout portion areintegrally connected by the remaining part of the dental mouthpiece.

It is more preferable that the dental mouthpiece includes a storagespace for storing the vibrating element inside; and that this storagespace has such a shape as to provide the vibrating element with a playpermitting the vibrating element itself to move in the storage space.

The play permits the vibrating element itself to move in the storagespace by a vibration load generated by the vibrating element. Thevibrating element permitted to make such movements collides with theinner surface of the dental mouthpiece enclosing the storage space.Loads caused by this collision can increase the vibration applied to theteeth of the user wearing the dental mouthpiece. This enables stimulisufficient to promote the orthodontic effect to be applied to the toothto be aligned while using a vibrating element that is small-sized andlightweight and generates a small vibration load.

The storage space is particularly preferably shaped such that aclearance is formed in the storage space in a direction corresponding toan aligning direction of the tooth to be aligned. Such a shape enhancesthe directivity of the vibration to be applied to the tooth to bealigned. For example, even if only the vibrating element having a lowvibration directivity (e.g. inexpensive and small-sized rotary motor orvibration motor) can be used because of cost and size, a vibration loadhaving high directivity can be applied to the teeth.

The dental mouthpiece preferably comprises an upper layer to be mountedon an upper teeth and a lower layer to be mounted on a lower teeth, thevibrating element being built in at least one of the upper and lowerlayers; and a connecting member connecting the upper layer and the lowerlayer at a position distanced from the tooth to be aligned.

The connecting member keeps the biting state (bite force and bitingsurfaces) of the upper and lower layers constant at the position wherethe vibrating element is built in, thereby preventing the user fromunconsciously biting the vibrating means and its neighboring part andthe bite from changing a way of transmitting the vibration. As a result,a desired orthodontic effect can be obtained by continuing to applydesired vibration to the tooth to be aligned while reducing burdens byeliminating the need for the user to make an effort to keep the dentalmouthpiece open.

The position of the connecting member is not limited. For example, thedental mouthpiece having the connecting member disposed at a positioncorresponding to the front teeth is suitable for the dental alignment ofthe molar teeth since it can ensure a constant biting state at a partcorresponding to the molar teeth by preventing the application of loadsgiven by the bite to this part. Further, the dental mouthpiece havingthe connecting member disposed at a position corresponding to the molarteeth is suitable for the dental alignment of the front teeth since itcan ensure a constant biting state at a part corresponding to the frontteeth by preventing the application of loads given by the bite to thispart. Furthermore, the dental mouthpiece having the connecting memberdisposed at a position more toward the back side than the molar teeth issuitable for the dental alignment of the entire teeth since it can bekept open by preventing the application of loads given by the bite toparts corresponding to both the front teeth and the molar teeth.

It is preferable that the orthodontic appliance according to the presentinvention further comprises a flexible board on which the vibratingelement is to be mounted; and that this flexible board includes acircuit for introducing power to the vibrating element and is built inthe dental mouthpiece together with the vibrating element.

The flexible board forms a power feeding path for introducing power tothe vibrating element mounted thereon. This power feeding path has afairly lower likelihood of breaking as compared to, for example, a powerfeeding path formed by drawing a lead wire out from the vibratingelement. Further, the use of the flexible board neither damages thedental mouthpiece nor hurts the buccal cavity. Beside the vibratingelement, it is also possible to mount a control circuit and a powersource for the vibrating element on the flexible board.

Further, if a board side connector for the external connection ismounted on the flexible board, a wiring operation for connecting thevibrating element and an external circuit of the dental mouthpiece canbe facilitated. This wiring operation is carried out, for example, by amethod comprising a step of exposing a part of the sealed flexible boardcorresponding to the board side connector from the dental mouthpiece, astep of connecting a lead-wire side connector attached to a lead wire tobe drawn out with the exposed board side connector, and a step ofsealing the exposed part again. This method remarkably simplifies thewiring operation as compared to a method including a step of exposing awiring pattern of the sealed flexible board from the dental mouthpiece,a step of soldering a lead wire to be drawn out to the wiring pattern,and a step of sealing the exposed part again.

Further, with an appliance comprising a lead wire drawn out from theboard side connector and a tube made of the same material as the dentalmouthpiece and adapted to cover the lead wire, a part where the leadwire is drawn out from the dental mouthpiece can also be sealedutilizing the tube. Specifically, a part of the sealed flexible boardcorresponding to the board side connector is exposed from the dentalmouthpiece, and the lead-wire side connector connected with the leadwire to be drawn out is connected with this board side connector.Thereafter, a drawn-out portion is sealed airtight by performing a stepof uniting an end of the tube with the exposed part for the connectionof the connectors, for example, by melting this end of the tube.

More preferably, the flexible board is so built in the dental mouthpieceas to extend in the direction of the teeth and formed with a wiringpattern extending in the longitudinal direction thereof, a plurality oflands used to solder the vibrating element being formed at a pluralityof positions of the wiring pattern.

With this flexible board, even if the shape of the flexible board isstandardized beforehand, the vibrating element can be arranged at anoptimal position by selecting the land to which the vibrating elementshould be soldered from those provided on the flexible board. Thisenables the vibrating element to be mounted on the flexible board at amost suitable position for the tooth to be aligned even if the tooth tobe aligned differs from user to user, with the result that theversatility of the flexible board can be improved and the cost of theappliance can be reduced. It is also possible to mount a plurality ofvibrating elements on one flexible board and to simultaneously drivethem.

If the vibrating element includes a motor having an output shaft and aneccentric weight mounted on the output shaft, a cover member forcovering the eccentric weight is more preferably so fixed to theflexible board as to define a space necessary for the rotation of theeccentric weight. This cover member effectively suppresses the hindranceof the eccentric weight to the satisfactory rotation of its own by thecontact of the eccentric weight with the inner surface of the dentalmouthpiece.

The present invention is also directed to a method for producing anorthodontic appliance comprising a vibrating element for generatingmechanical vibration and applying the vibration to a tooth to be alignedof a user, and a dental mouthpiece having the vibrating element builttherein and mountable on teeth of the user including the tooth to bealigned with the vibrating element built therein, the orthodonticappliance promoting dental alignment by transmitting the mechanicalvibration to the tooth to be aligned, the method comprising: a firststep of forming an inner layer constituting an inner part of the dentalmouthpiece by placing a sheet member having a heat softening property ona dental cast of the user with the sheet member heated to be softenedand closely attaching the sheet member onto the dental cast; a secondstep of mounting the vibrating element on the inner layer; and a thirdstep of setting the inner layer having the vibrating element mountedthereon on the dental cast of the user, placing a sheet member having aheat softening property on the inner layer with the sheet member heatedto be softened, and closely attaching the softened sheet member to theinner layer, thereby forming an outer layer constituting an outer partof the dental mouthpiece and sealing the vibrating element airtightbetween the outer layer and the inner layer.

According to this method, the dental mouthpiece having the inner andouter layers can be efficiently produced. Specifically, one dentalimpression is sufficient to form the outer layer, thereby reducing thenumber of operation steps. According to this method, instead ofreheating the hardened inner layer and outer layer and bonding those toeach other, the sheet member of the inner layer and that of the outerlayer half molten by the heat of the mounted outer layer and the heattransferred from the outer layer to the inner layer are naturallyunited. Therefore, a dental mouthpiece having high airtightness and highquality can be formed.

In the second step, the vibrating element can be attached to the innerlayer utilizing an adhering force of the material of the inner layergiven by the remaining heat of the inner layer. This method obviates theneed for another fixing means such as adhesive or enables the vibratingelement to be simply temporarily fixed to the inner layer while reducinga used amount of another fixing means.

In the first step, a sheet member made of a resin whose softeningtemperature is lower than the heat resistant temperature of thevibrating element is preferably used as the sheet member for forming theinner layer.

This construction enables the sheet member for forming the inner layerto be placed on the vibrating element while avoiding the trouble of thevibrating element due to a high temperature.

What is claimed is:
 1. A method for producing an orthodontic appliancecomprising a vibrating element for generating mechanical vibration andapplying the mechanical vibration to a surface of a tooth of a user tobe aligned, and a dental mouthpiece having an inner layer mounted onteeth of the user including the tooth to be aligned and an outer layerwhich is superimposed on the outer side of the inner layer with thevibrating element encapsulated between the inner side of the outer layerand the outer side of the inner layer in an watertight manner theorthodontic appliance promoting dental alignment by transmitting themechanical vibration of the vibrating element to the surface of thetooth to be aligned, the method comprising: forming the inner layer byheating a first sheet member having a heat softening property so as tosoften the first sheet member and placing the heated and softened firstsheet member on a dental cast to the teeth of the user and closelyconforming a shape of the first sheet member to the shape of the dentalcast; mounting the vibrating element on the inner layer, the vibratingelement being positioned so as to apply a vibrating force to the surfaceof the tooth; and heating a second sheet member having a heat softeningproperty so as to soften the second sheet member and placing the heatedand softened second sheet member on the inner layer on which thevibrating element has been mounted, conforming and closely attaching thesecond softened sheet member to the inner layer and to the vibratingelement, thereby forming the outer layer constituting an outer part ofthe dental mouthpiece and sealing the vibrating element between theouter layer and the inner layer in an watertight manner and such thatcontacting surfaces of the inner and outer layers are fused together. 2.The method according to claim 1, wherein, in the mounting, the vibratingelement is attached to the inner layer utilizing an adhering force ofthe first sheet member resulting from a remaining heat of the innerlayer.
 3. The method according to claim 2, wherein a sheet member of aresin with a softening temperature lower than the heat resistanttemperature of the vibrating element is used as the first sheet memberfor the inner layer.
 4. The method according to claim 1, wherein a sheetmember of a resin with a softening temperature lower than the heatresistant temperature of the vibrating element is used as the firstsheet member for the inner layer.
 5. The method according to claim 1,wherein, in the forming, a dental impression is obtained with bracketsand an orthodontic wire mounted on the dental cast corresponding to theteeth of the user.
 6. The method according to claim 5, wherein, in theforming, dental wax is provided in clearances existing between portionsof the dental cast corresponding to the brackets and to the orthodonticwire.
 7. The method according to claim 1, wherein the first sheet memberand the second sheet member comprise a same material.
 8. The methodaccording to claim 7, wherein the first and second sheets compriseethylene vinyl acetate (EVA).
 9. The method according to claim 1, thevibrating element including lead wires, the heating of the second sheetmember further comprising peeling off a portion of the second sheetmember corresponding to a location of the lead wires of the vibratingelement and connecting a power feed cable to the lead wires.
 10. Themethod according to claim 1, wherein the mounting comprises mounting aflexible circuit board having the vibrating element attached thereto tothe inner layer while the inner layer retains heat from the forming. 11.The method according to claim 1, wherein the inner layer and the outerlayer cover a dentition of the teeth.
 12. The method according to claim1, wherein the inner and outer layers have a shape conforming to a shapeof the dental cast, and the vibrating element mounted between the innerlayer and the outer layer comprises a projection extending from theshape of the attached inner and outer layers.
 13. The method accordingto claim 1, wherein the first and second sheets comprise ethylene vinylacetate (EVA).
 14. The method according to claim 1, wherein closelyattaching the second softened sheet member to the vibrating membercomprises forming a bulge corresponding to the vibrating member in thesecond sheet at a location corresponding to the tooth to be aligned. 15.The method according to claim 1, wherein the mounting of vibratingelement comprises mounting a plurality of vibrating members at aplurality of positions corresponding to teeth to be aligned.
 16. Themethod according to claim 15, wherein closely attaching the secondsoftened sheet to the inner layer and to the plurality of vibratingelements comprises fusing the inner layer and the outer layer togetherwith the plurality of vibrating elements encapsulated between the innerside of the outer layer and the outer side of the inner layer.
 17. Themethod according to claim 15, wherein, in the mounting, the plurality ofvibrating elements are attached to the inner layer utilizing an adheringforce of the first sheet member resulting from a remaining heat of theinner layer.
 18. The method according to claim 15, wherein a sheetmember of a resin with a softening temperature lower than a heatresistant temperature of the plurality of vibrating elements is utilizedas the first sheet member for the inner layer.
 19. The method accordingto claim 1, wherein the first sheet member has a hardness different thana hardness of the second sheet member.
 20. The method according to claim1, wherein closely attaching the second softened sheet member to theinner layer and to the vibrating element comprises fusing the innerlayer and the outer layer together with the vibrating elementencapsulated between the inner side of the outer layer and the outerside of the inner layer.